Mechanism for actuating powered wire tensioning device



H. K. EMBREE June 22, 1965 MECHANISM FOR ACTUATING POWERED WIRE TENSIONING DEVICE Filed Dec. 16, 1963 5 Sheets-Sheet 1 m kn omuuunulunnm. on m mm E VQ No hm kw mm W kw INVENTOR HAROLD K. EMBREE O BY A Q ATTORNEYS.

J1me 1965 H- K. EMBREE 3,190,613

MECHANISM FOR ACTUATING POWERED WIRE TENSIONING DEVICE Filed Dec. 16, 1963 3 Sheets-Sheet 2 FIG. 2.

lNvENToR HAROLD K. EMBREE ATTORNEYS.

June 22, 1965 H. K. EMBREE Filed Dec. 16, 1963 MECHANISM FOR ACTUATING POWERED WIRE TENSIONING DEVICE 3 Sheets-Sheet 3 United States Patent 3,190,613 MEUHANKSM FOR AQTUATHNG POWERED WERE TENSHUNING DEVHCE Harold K. Embree, Hamilton, Ontario, Canada, assignor to Uvalstrapping Limited, Toronto, Ontario, Canada Filed Dec. 16, 1963, Ser. No. 331L721 Ulla-inns. (Cl. 254-51) This invention relates to a device for tensioning baling wire about a bale or similar package.

Known tensioners suffer preeminently from the drawbacks that they are difficult to manoeuver, somewhat clumsy in operation and in the main, require the combined and simultaneous use of both of the operators hands in order to achieve their satisfactory operation. The present 5 vention provides a compact and easily operable device which permits a single handed operation.

The present invention overcomes previous disadvantages by the provision of the single, hand operating lever on a wire tensioning device which causes in a single oporation, a wire tensioning roll to resiliently move to an operative wire engaging position closer to another wire tensioning roll for gripping a wire therebetween and thereafter to operate the motor for rotating at least one of said rolls whereby to cause the Wire to be drawn through the rolls and thereby tensioned.

Preferably a gripping means is mounted on the frame of the device to prevent a wire being tensioned thereby from becoming slack when its tensioning rolls are not being rotated.

In a preferred embodiment the motor is an air turbine, supplied with pressurized air from an external source which passes through an air control valve, to drive the tensioning rolls of the wire tensioning device.

Preferably the rolls are knurled and may be replaced by rolls of a different diameter, thereby to permit the device to accommodate wire of different gages.

The following is a description of one embodiment of the invention, by way of example, reference being had to the accompanying drawings wherein:

FIGURE 1 is a side elevation view of the tensioning device, being partially in section to show the air control valve;

FIGURE 2 is a cross sectional view taken along the section line 2-43 of FIGURE 1, and showing the gears and shaft which drive the tensioning rolls; and

FIGURE 3 is a view partially in section, looking at the device of FEGURE 1 from the reverse side.

Turning now to the drawings, reference character 1 denotes a main frame of a wire tensioning device. Mounted on the frame are tensioning rolls 29 and 33. An air turbine 61, also carried by the frame 1, is connected through gear means 59 to the tensioning rolls 29 and 3%. A hand operating lever 2 is pivotally connected to the frame 1 and is adapted to move the tensioning rolls 29 and 38 toward each other, in a manner which will presently become apparent, to grip a wire placed therebetween and also to open a control valve in to supply pressurized air to drive the air turbine and thus to cause the rolls to rotate.

The operating lever 2 having cam surfaces 12 and 13 is pivotally mounted on a pivot bushing 6 between a thrust plate 4 and a cover plate 5. A screw 3 passing through the bushing 6 secures the bushing to the main frame :1. The lever 2 is provided with a ball 7 to permit the operator to grasp it in an easy manner. A roll mounting means 14 located between the lever 2 includes an arm 17 which is pivotally mounted on bushing 15 which itself is secured to the frame 1 by a screw 16. A press bar 29 is held by shoulders 21 in a slot 22 formed in the top section of the arm 17. The left end of the press bar, immediately under the lever 2 as seen in FIGURE 1, has

3.1%,613 Patented June 22, 1965 a thickness which is less than the depth of slot 22 and springs 23 seated in pockets 24 formed in the arm force the press bar tightly against the shoulder 21.

A spring loaded plunger 25 seated in a pocket 26 formed in the frame 1 bears against the bottom of the arm 17 and forces it upward so that the press bar 20 is forced against the bottom of the lever 2. Mounted in the bore 27 (see particularly FIGURE 2) in the arm 17 is a shaft 30 which is free to rotate in bearings 31. A shaft 32 is rotatably mounted in bearings 33 fitted in bore 28 in the frame 1, immediately below shaft 30. The ends of the shafts 30 and 32 project outward from the sides of the arm 14 and frame 1, respectively, and are provided with circumferential grooves 35 and keyways 37. The tensioning rolls 29 and 38 have internal diameters 3 and 49, respectively, corresponding to the diameter of the ends of the shafts are kept from sliding off of the shaft by snap rings 36 and prevented from rotating on the shaft by keyways 40 and Woodruff keys 34. The circumferential surfaces of the rolls are preferably knurled to improve the gripping action on a wire when gripped between them. A thrust plate 41 is provided to prevent axial movement of the rolls. The lower shaft 32 passes through a circular hole 43 in the thrust plate 41 and the upper shaft 30 passes through a slotted hole 4-2 to allow the shaft 30 to move towards and away from the bottom shaft 32. Oil seals 44 are located immediately inside of the thrust plate 41 to prevent oil from escaping through the bearings 31 and 33 from the gear boX 45.

The end 48 of a valve plunger 46 mounted in a bore 47 in the main frame 1 projects from the frame and is located so as to cooperate with the cam surface 12 as the lever 2 is moved to the right as seen in FIGURE 1. As the plunger 46 is moved into the frame it forces a ball 50 of a control valve '70 off on an O ring 51 fitted in the valve seat 52. Air is then allowed to pass from an external source through a threaded connection screwed into the tapped hole 53, through the ports 58 in the ball chamber 54 and by Way of port 68 in the seat 52 into the small chamber 56 in the bore 47 formed around the reduced end portion of the plunger 47. From chamber 56, it is free to flow through the passage 57 to the port 60 of the air turbine 61. An 0 ring 67 is fitted in groove 62 in plunger 46 to prevent air from escaping through the plunger bore 47. The ball 50 is biased towards its seat 52 by a spring mounted in a valve cage 63 which is screwed into the opening 64 in the frame 1. When the lever Z is returned to the neutral position shown in FIG- URE 1, the spring 65 forces the ball to the seated position, and the ball acting on the plunger 46 forces it back to its original position. Once the ball has been seated, the air pressure in the ball chamber 56 aids in keeping the ball seated and thus prevents the passage of air through to ports 61). The cage 63 has a circumferential groove to receive the O ring 67 to insure that air does not escape around the cage.

Chamber 71 (see FIGURE 3) in the frame 1 houses the air turbine motor 61 having a main shaft 72 mounted in bearings '73 and 74. The outer end of the chamber is sealed by a cap '75 which is screwed into the threaded end of the chamber. The air entering the chamber through port 66 acts on the blade 76, causing them to rotate the main shaft '72 of the turbine. The end 77 of the main shaft '72 projects into the centre of a planetary gear train 80 and has teeth 31 cut thereon to serve as the sun gear of the gear train. The planet gears, one of which is denoted by the number 83 mesh with the teeth 81 and the ring gear 32 which is secured to the frame 1. The planet gears are provided with roller bearings 83 which permit them to turn freely on the planet pins 87 mounted in planet cage 35. The planet cage has a projecting shaft 86 having a worm gear 9% formed thereon.

The cage 85 and its shaft 86 rotate in bearings 84 and 91. The end of the chamber 89 housing the shaft 86 is closed by a bearing adjustment plug 92.

The worm gear 99 meshes with the worm wheel 93 formed on shaft 32. The left end of the shaf as seen in FIGURE 2, is rotatably mounted in the frame by hearing 95. A hearing locking cap 98 which also closes the gear box 45 forces the bearing 96 against the shoulder N1 formed in the frame 1 to prevent axial displacement of the hearing. The bearing 96 in turn prevents axial displacement of the shaft 32 since the bearing is mounted between a shoulder 1th) on the shaft and a snap ring 97 seated in a circumferential groove 162 in the shaft. Gear teeth 94 are also formed on shaft 32 and these teeth mesh with gear 95 formed on the end of shaft 30. Axial displacement of shaft 39 is prevented by a thrust washer 103 mounted on the shaft and bearing against the arm 17.

As best seen in FIGURE 1, a gripping means 99 is provided in line with the rolls 29 and 38. A gripping anvil 104 with a wire engaging surface 109 is located on the frame 1, and a gripping lever 105 is pivoted to the frame by a thumb screw 105 above the anvil. The gripping lever is provided with a gripping element 118 having a wire engaging surface 197. The gripping element 118 is pivotally connected to the lever 1635 by a pivot pin 123. The lever 105 has a flat surface 1% against which the operator may press to pivot the lever as shown by the arrow 113 in FIGURE 1. A spring lever 110 is biased towards the frame by a spring 11, the end of which encircles the lever. The other end of the spring encircles a pin which is attached to the frame. The spring lever 110 in turn bears against the projection 111 of the gripping lever 165 forcing it in a counterclockwise direction as seen in FIGURE 1 and thus biases the gripping surface 167 against wire engaging surface 109. The upper end of the lever spring 119 fits into a socket 112 which allows the spring lever to pivot about its upper end. The lever lock 119, which comprises a fiat plate portion 114 and a projection 116, is pivotally connected to the frame and is free to swing in between an enlarged portion 115 of the gripping lever 1G5 and the frame when the gripping lever is forced in the direction of the arrow 113 as shown in FIGURE 1. A wire-catch slide 120 is mounted to slide in channel 121. The wire passes between the member 120 and the frame to prevent it from riding off of the end of the rolls 29 and and to guide it into gripping means 99. Tapped holes 122 are provided in the base portion 9 of the frame 1 to permit the attachment of a unit for holding the end of the wire which has been passed around the bale and for securing the end to the tensioned strand passing through the tensioning device to secure the bale.

In operation, it is not necessary to thread the end of the wire to be tensioned through the tensioning device since a strand of wire passing the device can be fed laterally into it. By pressing on surface 168 the operator forces the gripping lever against the force exerted by spring lever 119. The lever lock 119 is then free to swing in between the enlarged portion 115 of the gripping lever 195 and the frame 1, thus preventing the lever 1&5 from rotating counterclockwise as seen in FIGURE 1 When the operator releases it. Considerable space is then left between the wire engaging surface 109 of the anvil and gripping surface 107 of the gripping lever. The wire can then be laterally inserted into the gripping means and between the rolls 29 and 38 since they are forced apart by the plunger 25. As the wire is inserted into the gripping means, the operators hand engages the projection 116 of the lever lock 119 and thus forces the member 114 away from the enlarged portion 115 of the gripping lever 105 and permits the gripping lever to swing into a position to grip the wire between surface 107 and the gripping anvil 104. At this point slide 129 is raised and lowered to trap the wire between it and the frame.

When the operator pushes the lever 2 in the direction opposite to that shown by the arrow 117 in FIGURE 1, the cam surface 13 of the lever forces press bar 2i) downwards. The force is transmitted through the springs causing the arm 14 to pivot downwards also. This causes the roll 29 to move to its wire engaging position, and the wire is clamped between the two tensioning rolls 29 and 38. Eventually, the cam 12 of the lever 2 contacts the end 48 of the plunger 46 and as the lever 2 is pushed to tl e extreme right, it unseats the ball 50 allowing air to pass through the control valve and drive the air turbine motor. The rotation of the main turbine shaft 72 causes the planet cage to rotate at an rpm. less than the rpm. of the shaft 72. The shaft 32 on which the lower tensioning roll 38 is mounted, is driven by worm meshing with worm wheel 93. The top tensioning roll 29 mounted in arm 14- rotates in the opposite direction since the gear formed on the shaft 30 meshes with the gear 94 formed on the shaft 32. The wire which is tightly gripped between the rolls 29 and 38 is forced from right to left as seen in FIGURE 1 by the rotation of the rolls, and the gripping means 99 allows the wire to pass through it in this direction. The pressure of the air entering the device is set at a predetermined value so that the turbine will stall when the desired tension of the wire is reached.

Thus, it can be seen that the present invention enables the operator, by the manoeuvering of the single lever 2, to control the gripping of the wire between the rolls 29 and 38, and to bring about the operation of the motor 61 to drive the rolls and tighten the wire. The construction of the device ensures that the wire is firmly gripped between the rolls before the motor 61 is started to drive the rolls.

When the motor stalls, the lever 2 is returned by the operator to the neutral position allowing the valve 70 to cut off the air supply to the turbine and permits the spring loaded plunger 25 to push the top tensioning roll 38 out of engagement with the wire and into an inoperative position. The Wire is held by the gripping means 99 and prevented from travelling back through the tensioning rolls and becoming slack. The operator is then free to twist the strands of wire together or by other means fasten them to form a tensioned loop around the bale.

A wire having a cross-section other than circular, for example fiat or oval, can be used with this wire tensioning device. The tensioning rolls 29 and 38 can be easily removed from the shafts 3t and 32 by first removing the snap-rings 36 from the grooves 35 in the shafts. By replacing the tensioning rolls with rolls having outer diameters differing from the diameters of the removed rolls, the device can accommodate wire of different gages and thicknesses.

As previously stated, the tension of the wire is governed by adjusting the air pressure entering the motor to a predetermined value. Similar results can be achieved by replacing the air turbine motor with an electric motor and an adjustable torque limiting clutch. In this case, the air control valve can be replaced by an electric switch which would also be controlled by a plunger 46 or like element. Thus, when the electric switch is activated by the operation of the lever 2, electricity is supplied to the electric motor which drives the rolls 29 and 38 through a torque limiting clutch. When the wire reaches the desired position, the clutch begins to slip and in this manner disconnect the motor from the rolls.

What I claim as my invention is:

1. A wire tensioning device comprising a first tensioning roll, a second tensioning roll mounted on a pivoted arm for movement relative to said first roll, operating means including a hand operated lever for pivoting said arm thereby to move said second roll from an inoperative position towards said first roll to an operative wire engaging position, said operating means further including a cam surface for controlling a motor which drives said first and second tensioning rolls in opposite directions when the second roll is in said operative position, whereby to draw a wire to be tensioned between said rolls.

2. A wire tensioning device as claimed in claim 1, further comprising gripping means to prevent the Wire from becoming slack when the tensioning rolls are not being driven by said motor.

3. A wire tensioning device as claimed in claim 1, in which means is provided to bias said second roll to the inoperative position.

4. A wire tensioning device as claimed in claim 1, in Which the rolls are removable and interchangeable with rolls of different diameters.

5. A wire tensioning device comprising a first tensioning roll, a second tensioning roll mounted on a pivoted arm for movement relative to said first r011, operating means for moving the second roll from an inoperative position to an operative wire engaging position closer to the first roll, said operating means including a hand-operated lever having a cam surface thereon profiled such that,

References Cited by the Examiner UNITED STATES PATENTS 2,541,833 10/48 Koch 226176 2,590,806 3/52 Vorderstrasse 226176 X 2,594,397 4/52 Childress et al.

2,884,825 5/59 Eubanks 81-9.51 3,118,473 1/64 Bell 25451 X WILLIAM FELDMAN, Primary Examiner.

MILTON S. MEHR, Examiner. 

1. A WIRE TENSIONING DEVICE COMPRISING A FIRST TENSIONING ROLL, A SECOND TENSIONING ROLL MOUNTED ON A PIVOTED ARM FOR MOVEMENT RELATIVE TO SAID FIRST ROLL, OPERATING MEANS INCLUDING A HAND OPERATED LEVEL FOR PIVOTING SAID ARM THEREBY TO MOVE SAID SECOND ROLL FROM AN INOPERATIVE POSITION TOWARDS SAID FIRST TO AN OPERATIVE WIRE ENGAGING POSITION, AND OPERATING MEANS FURTHER INCLUDING A CAM SURFACE FOR CONTROLLING A MOTOR WHICH DRIVES SAID FIRST AND SECOND TENSIONING ROLL IS OPPOSITE DIRECTIONS 